Continuous muller



K. H. ANDRAE Deo. 13, 1966 CONTINUOUS MULLER 2 Sheets-Sheet l Filed March 1.7, 1964 eu B3, W66 K. H. ANDRAE m@ CONTINUOUS MULLER Filed March 17, 1964 ,2 sheets-sheet IIE INVENTOR; KARL HANDRAE,

United States Patent O 3,291,460 CONTINUOUS MULLER Karl H. Andrae, Columbus, Ohio, assignor to Jeffrey Glalion Manufacturing Company, a corporation of O io Filed Mar. 17, 1964, Ser. No. 352,579 Claims. (Cl. 259-109) The instant invention relates to the mulling of materials, i or example, as is practiced in foundry operations in respect to the preparation of sand for making molds, and more particularly, to improvements in a continuous mulling apparatus.

This invention has application to the treatment of materials by mulling, for example, the mulling of sand in a foundry to place the same in suitable condition for use in making molds in metal casting operations. The mulling of the sand may involve new sand which has not previously been used in making molds, recirculated sand which has been used in molds and is circulated in the foundry system for reuse, or a combination of the two. In any of these cases it is required that the sand be mulled, which involves adding to the sand and combining therewith certain ingredients, particularly water and bonding agents. In the mulling operation, it is desired that these ingredients be uniformly combined with the mass of sand, and in an ideal operation each grain of sand is completely and uniformly coated with the added ingredients, whereby the mass of sand discharged from the mulling operation has the necessary bonding characteristics, such that it may be formed into molds into which hot molten metal may be poured.

The mulling -of the sand is essentially a pressing, kneading and mixing operation in which the sand and the added ingredients are constantly being pressed, kneaded and mixed until the added ingredients are uniformly dispersed in the mass of sand, and the grains of sand are each coated with the bonding materials. In mulling operations, in which recirculated sand is being operated upon, such sand is usually very hot as the result of being in contact with hot molten metal, and is far hotter than is desired for the mulling operation or for the formation of molds. In such case it is necessary that the sand be cooled, and this may be accomplished during the mulling operation by circulating air through the sand, in addition to the tempering -water that is added. Also in connection with the preparation of the sand for the making of molds, it is desired that the sand be aerated, which consists essentially of breaking up any lumps in the sand and placing the mass of sand in a loose, uniform condition, in which it may be readily and uniformly packed around a pattern in the process of making a mold with such sand.

It is an object of the instant invention to provide an improved continuous apparatus for the preparation of materials by mulling, for example, sand to be used in the making of molds.

It is another object of the instant invention to provide an improved apparatus for the mulling of materials, which is continuous in its operation and through which the materials continuously ow, such flow of the materials being retarded to provide a retention time of the materials in the apparatus of sucient length as to effectively mull the same.

It is another object of the instant invention to provide an improved apparatus for the mulling of materials, in which the material continuously flows through the apparatus and is dispersed therein for mulling.

It is a further object of the instant invention to provide an improved mulling apparatus in which there is provided a plurality of mulling assemblies which successively mull the material as it ilows through the apparatus.

3,291,460 Patented Dec. 13, 1966 ice Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the drawings:

FIG. l is a longitudinal, elevational view of the continuous muller constructed in accordance with this invention, partially in section;

FIG. 2 is a transverse sectional view of the continuous muller, taken on the line 2-2 in FIG. 1;

FIG. 3 is an elevational View of a mulling assembly, viewed on the line 3 3 in FIG. 2;

FIG. 4 is a sectional view of a typical mulling assembly, taken on the line 4 4 in FIG. 2; and

FIG. 5 is an elevational view of the sweeper blade, viewed on the line 5-5 in FIG. l.

The continuous muller 10, constructed in accordance with the instant invention, comprises a cylindrical drumlike receptacle 11 placed on a substantially horizontal axis, whereby the cylindrical receptacle 11 is disposed in a lateral position extending along its axis. The receptacle 11 is supported on feet 12, 13 which may be formed of steel plate that is shaped to the desired configuration and secured to the receptacle 11 in a suitable manner, as by welding. The feet 12, 13 are placed at opposite ends of the receptacle 11 for securing the continuous muller 10 to a supporting base 14, as by a plurality of bolts.

The receptacle 11 includes a cylindrical shell 15. The feed or upstream end of the cylindrical shell 15 is closed by an end wall 16, and the discharge or downstream end of the cylindrical shell 15 is closed by a similar end wall 17. Each of the end walls 16, 17 is formed of a plate having a disc-like form. The cylindrical shell 15 and the end walls 16, 17 are preferably formed of steel plate, or the like, with the end walls 16, 17 being received within the ends of the cylindrical shell 15 and being secured thereto, as by welding, whereby the receptacle 11 is a rigid structural sub-assembly of the continuous muller 10. For the purpose of further rigidifying the receptacle 11, a plurality of longitudinally extending ribs 18 are secured to the outer wall of the cylindrical shell 15, as by welding (FIG. 2). The ribs preferably are radially disposed on the cylindrical shell 15. At the top of the cylindrical shell 15 there are secured two apertured ears 19, one at each end thereof, in which crane hooks may be received for raising and lowering the continuous muller 10 when it is necessary to move the same.

The receptacle 11 is provided with an opening that extends the full length thereof in an upper quadrant of the cylindrical shell 15, as best seen in FIG. 2. The opening is illustrated as being of lesser arcuate length than however, `it will be understood that the size of the opening is governed by the need for reaching inside the receptacle 11 for maintenance of the various elemtns of the continuous muller 10 that are contained therein. The opening is closed by a cover 20 which forms a continuation of the cylindrical shell 15, and in eifect, completes the cylindrical shell 15 when the cover 20 is in its closed position, as seen in FIG. 2.

The cover 20 is connected to the receptacle 11 at each end thereof by a hinge 21 having a longitudinally extending axis, whereby the cover 20 may be readily raised to its open position, as partially seen in FIG. l. To'facilitate raising the cover 20, there may be provided a pneumatic cylinder, or like device, of which the piston rod 22 lhas a clevis 23 at its upper end by which it is connected to a depending ear 24 with a pivot pin 25. The cover 20 is then opened and closed by extension and retraction, respectively, of the piston rod 22. Suitable controls may be provided for extension and retraction ofv At the lower edge of the receptacle opening there is a longitudinally extending locking bar 26 which projects outwardly from the cylindrical shell 15. The lower edge of the cover 20 has a like, longitudinally extending locking bar 27 which is secured thereto and is disposed to be in parallel position to the locking bar 26 when the cover 20 is in its closed position. The cover 20 is locked by special locking bolts 28, several of which are disposed along the locking bars 26, 27 to secure the locking bars 26, 27 to each other. Each locking bolt 28 includes a boss 29 which is disposed between a pair of upright ears 30, the latter being secured to the upper surface of the locking bar 27. A pivot pin 31 extends through the boss 29 and the ears 30 to provide a pivotal connection of the boss 29 and the bolt 28 to the cover locking bar 27. The locking bars 26, 27 are formed with lateral slots 32, 33, respectively, which are aligned with the bolts 28 so that the bolts 28 may be swung about their pivot pins 31 and through the slots 32, 33. A nut 34 is threaded on the bolt 28 and a washer 35, or the like, is secured to the end of the bolt 28 to form a retaining flange to prevent the nut 34 `from being removed from the bolt 28.

Normally, the bolt 2S is disposed in depending position, as seen in FIG. 2, and extends through the locking bars 26, 27. The nut 34 is turned up on the bolt 28 against the under side of the locking bar 26, thereby locking the cover 20 in closed position. When it is desired to open the cover 20, a first step is to turn each of the nuts 34 down on the bolts 28 and to swing the bolts 28 upwardly about their respective pivot pins 31. This releases the cover locking bar 27 from the lower locking bar 26 and permits the -cover 20 to be raised as previously described.

Referring now to FIG. 1, there is a shaft 36 that eX- tends through the receptacle 11, with its laxis coincident with the axis of the cylindrical shell 15. The opposite ends of the shaft 36 lare rotatably supported on the end walls 16, 17. The means Ifor rotatably supporting the opposite ends of the shaft 36 are the same, and accordingly, such supporting means will be described only with respect to the end of the shaft 36 at the feed or upstream end of the receptacle 11, it being understood that the description applies to the like supporting means at the discharge or downstream end of the receptacle 11 for the other end of the shaft 36.

The end wall 16 has a centrally disposed circular opening 37 which is considerably larger than the diameter of the shaft 36, and the shaft 36 extends through such opening 37. Within the opening 37, at the outer side of the end wall 16, there are placed two halves of a disc-like retainer 38, the latter having a central aperture through which the shaft 36 passes. The opening 37 is filled with a felt packing seal 39 that is placed adjacent to the disc 3S. The felt seal 39 fills the opening 37 and forms a seal against the periphery of the shaft 36. The felt seal 39 is held in the opening 37, at the inside of the wall 16, by a pair of rectangular retainer plates 40, 41, ras seen in FIG. 2. The plates 40, 41 are secured to the end wall 16 by a plurality of bolts 42. The rectangular plates 40, 41 have semi-circular cutouts, so that when placed side by side as shown, there is formed a circular opening through which the shaft 36 passes. Upon securing the plates 40, 41 to the end Wall 16, the packing 39 is compressed in the end wall opening 37 between the retainer 38 -and the plates 40, 41, whereby the packing 39 fills the opening 37 and seals the shaft 36 therein.

The shaft 36 projects beyond the end wall 16 and is formed with a reduced diameter end 43 that is received in a flange roller bearing 44 to be rotatably supported thereby. A ring 45 is disposed between the flange roller bearing 44 and the end wall 16. The ring 45 is secured to the end wall 16,`as by welding. The internal diameter of the ring 45 is smaller than the diameter of the opening 37, whereby the ring 45 `forms a shoulder t0 back the retainer 38 and to secure the latter in the open= ing 37. The flange roller bearing 44 is secured to the ring 45 and the end wall 16 by a plurality of bolts 46, or the like, as seen at the left in FIG. 1. The ring 45 is partially cut away to provide an opening 47 at the bottom thereof, which is of substantial size. Any material which might get past the felt seal 39 will drop to the bottom of the ring 45 and out through the opening 477 and thereby such material is prevented from Working its way into the flange roller bearing 44. A shaft guard 48 is secured to the end wall 16 below the ring 45 and extends upwardly therefrom to the exposed end of the reduced diameter shaft end 43. The shaft guard 48 has a cup 49 which covers the shaft end 43. The shaft guard 48 is bolted to a channel support 50, which is secured to the end wall 16, as by welding. The shaft guard 48 is installed on that end of the continuous muller 10 that is the nondriven end. Suitable driving means is connected to the other end of the shaft 36 to rotate the same.

The end wall 16 has a feed opening 51 disposed at one side of the shaft 36, and at the opposite side there is a rectangular opening 52 for the supply or exhaust of a current of air that may flow through the muller receptacle 11. A feed chute 53 terminates at its bottom in an opening that is aligned with and connects with the feed opening 51 for the discharge of sand into the muller receptacle 11. An air duct 54 connects to the rectangular opening 52 for the flow of air through the continuous muller 10, which may be concurrent with the direction of feed of material through the muller 10, or countercurrent there- The sand is received in the muller receptacle 11 at the feed or upstream end and then Hows in a downstream direction through the receptacle 11 to the downstream or discharge end thereof, at which there is a discharge section 55 from which the ysand discharges through the discharge chute 56. As the sand flows through the receptacle 11, it is successively mulled by a plurality of successive mulling assemblies 57a, 57b, 57C, 57d, 57e, 571, 57g, 57h, all of which are identical, except for the mulling assembly 57a which has an additional element, as will be described hereinafter. In the interest of clarity, FIG. 1 includes a complete illustration of only the mulling assemblies 57a, 57b, which are the first and second mulling assemblies in the direction of flow from upstream to downstream. The remaining mulling assemblies 57c-h are merely represented -by an outline of the mulling wheels and plows thereof. The description of the mulling assemblies 57a, 57b is applicable to the mulling assemblies 57c-h, except as to the one added element of the mulling asembly 57a, as will be specifically Imentioned hereina ter.

The several mulling assemblies 57a-z are secured to the shaft 36 to be moved thereby about the axis of the shaft 36. The mulling assemblies 57a-l1 are disposed at equally spaced positions along the shaft 36 between the feed or upstream end of the mulling receptacle 11 and the discharge section 55, Thus, as the sand flows through the muller receptacle 11 from the feed or upstream end thereof towards the discharge section 55 at the discharge or downstream end of the muller receptacle 11, the mulling assemblies 57a-h successively operate on and mull the the sand. The successive positions of the several mulling assemblies 57a-l1 along the shaft 36 are apparent in FIG. 1, and are further indicated by the letters a-h at the bottom of FIG. 1, identifying and locating the several successive mulling positions along the length of the -mulling receptacle 11.

For each mulling assembly 57a-h there is secured to the shaft 36 a partial hub 58, as best seen in FIG. 2. The hub 58, as illustrated herein, extends through an angle somewhat greater than 180, suicient to receive three -bolts at positions spaced relatively to each other. Each partial hub 58 is firmly secured to the shaft 36, as by Welding, for mounting a mulling assembly 57.

Referring to FIG. 2, there is illustrated therein the mulling assembly 57a, which is typical of the construction of the several lmulling assemblies 5711-11, with the exception that it includes an additional element that is not included in the mulling assemblies 57h-h, as will be specifically pointed out. The mulling assembly 57a is constructed on a frame 60'. The frame 6tl comprises a center hub portion 61 formed with an arcuate recess 62 that is open along a diametral line, whereby the frame 60 and the mulling assembly 57a may be placed over the shaft 36. The recess 62 is formed on a circular arc having a radius equal to the radius of the shaft 36. Thus, the frame 60 may be seated on the shaft 36. The hub portion 61 of the yframe 60, and the p-artial hub 58, are each formed with three apertures, which may be at 90 spaced positions relative to each other about the axis of the shaft 36. The apertures in the partial hub 58 and in the center hub portion 61 of the frame 60 are aligned with each other to receive three bolts 6-3, by which the frame 60 is secured to the partial hub 58 and is mounted on the shaft 36. In effect then, the entire mullin-g assembly 57a is secured to the shaft 36 'by the several bolts 63. By releasing the bolts 63, the entire mulling assembly 57a lmay be removed from the shaft 36 for replacement, repair or other maintenance of the salme as may be required.

The frame 68 further includes a first mounting arm 64 and a second mounting arm 65. The mounting arms 64, 65 are formed as extensions of the fra-me hub portion 61, and extend from opposite sides of the hub portion 6l. The outer end of the first mounting arm 64 is forimed with an integral sleeve 66. Within the sleeve 66 there are provided a pair of torsion bushings 67, which are press fitted in the bore of the sleeve 66, as seen in FIG. 4. Each torsion bushing 67 comprises a Lrnetal sleeve 68, on the outer surface of which there is bonded a cylinder 69 of rubber, or like yieldable material. The bond between the metal Vsleeve 68 and the outer rubber cylinder 69 causes the latter to be immovable relatively to the metal sleeve 68 at the metal-rubber junction. However, the rubber cylinder 69 is yieldable to an increasing extent as the radial distance of the rubber cylinder 69 increases from the junction of the rubber to the metal. lt is this yieldable characteristic of the torsion bushing 67 that is utilized in the milling assembly 57.

The two torsion bushings 67 are press fitted in the bore of the sleeve 66, whereby the rubber cylinders 69l are compressed, setting up a force pressing the rubber against the bore of the sleeve 66, as well as against the metal sleeve 68 of the torsion 'bushing 67. Such pressure, in effect, immovably secures the peripheral surfaces of the rubber cylinders 69 to the bore of the sleeve 66. Then, if there is a torsional force applied to the metal sleeves 68, such force is resisted by the rubber cylinders 69 which tend to maintain themselves in a neutral position in which they are not distorted. If the torsional force exceeds the -spring rate of the rubber cylinders 69, then there is relative rotation of the metal sleeves 68 and the sleeve 66.

A hub is formed with an integral shaft "71 that is received in the bores of the torsion bushings 67, and has a threaded end that projects beyond the torsion bushings 67. The hub 70 bears against 'an end of a metal sleeve 68 of the torsion bushings 67 that projects beyond the sleeve 66. whereby the hub '/'0 is spaced from lche one e-nd of the sleeve 66. A washer 72 is mounted on the projecting end of the shaft 71 and bears against an end of a metal sleeve 68 of the torsion bushings 16'7 Ithat projects beyond the end of the sleeve l66, to space lthe washer 72 from the other end of the sleeve 66. A nut 73 is turned on the threaded end of the shaft 70, whereby the hub 70l is pressed against one end of a metal sleeve 68 of the torsion lbushings `67, and the washer 72 is pressed against another end of -a metal sleeve 68 of t'he torsion bushings 6 67. In effect then, the hub 70 is fixedly secured to the metal sleeve 68 of the torsion bushings 67. There is no contact between the hub 70 yand the rubber cylinders 69 of the torsion bushings 67 by reason of the conical configuration of each end of the rubber cylinders 69.

The torsion bushings 67 are interposed between the Imounting `hub 70 andthe sleeve 66 of the frame 60. Thus, the hub 70 can rotate or pivot about the axis of its shaft 71 and relatively to the sleeve 66. However, the interposition of the torsion bushings 67 provides a yieldable means which resists such rotation or pivotal movement of the hub 70, to the extent of the spring rate of the rubber cylinders 69 of the torsion bushings 67.

A centrally disposed boss 74 projects from the outer side of the hub 70. A supporting lever 75 is formed with an aperture J76 in which Uhe boss 74 is received when the supporting lever 75 is mounted on the hub 70. The supporting lever 75 is fxedly secured to the Ihub 78 by a plurality of bolts 77, of which there may be three.

The supporting lever 75 has the form of a crank and comprises an outer yarm 78 land an inner arm 79. At the end of the outer arm 78 there is formed an integral axle 8f), the axis of which is parallel to the axis of the shaft 36. A first bearing 81 is mounted at the inner end of the axle abutting an annular shoulder 82. A second bearing 83 is mounted on the axle 80 at the outer end thereof, with a spacer 84 disposed between the bearings 81, 83 to maintain them in spaced apart positions. The axle 8i) has a threaded end 85 on which there is turned a nut 86 which secures the bearings 8l, 83 on the axle 80.

A mulling wheel 87 is rotatably mounted on the axle 8f), with the bearings 8l, 83 interposed between the mulling wheel hub 88 and the axle 8f). The bore 89 of the mulling wheel hub 88 is formed wtih a shoulder 90 at the inner end thereof against which the bearing 81 is seated. In the outer end of the bore 89 there 4is pflaced a spacer 91 which abuts the second bearing 83. The axle 8l) terminates short of the end of the bore 89. A cover 92 overlies the outer end of the bore 89 and is secured to the hub 88 by a plurality of bolts 93. An O-ring 94 is interposed between the cover 92 and the hub 88 to assure a seal therebetween. The cover 92 thus closes the outer end of the bore 89 and prevents material from get,- ting into the lbore 89 and contaminating the bearings 81, 83. The cover 92 also secures the space-r 91 in position against the second bearing 33 and thereby xes the position of the mulling wheel 87 on the shaft 80.

It is necessary that the inner end of the bore 89 also be sealed to prevent material from reaching the bearings 81, 83 and contaminating these. Accordingly, at the inner end of the bore 89 there is formed an outwardly fac- -ing annular seat 95. The outer arm 78 is also formed with an annular seat 96 which is aligned with and oppositely disposed with respect to the first annular seat 9S. Between the annular seats 95, 96 there is placed a rotating seal 97. Such rotating seal 97 comprises a pair of like, oppositely disposed metal rings 98, 99 that fhave Iabutting surfaces. The abutting surfaces of the rings 98, 99 have a superfine finish, such that the rings 98, 99 are rotatable relatively to each other, but by abutment of their superfine finished sur-faces there is malintained such an intimate contact of the rings 98, 99 with each other that there is effected a seal between the relatively rotating rings 98, 99. An elastic ring 100 is disposed between the first anular seat and the metal ring 98, and a similar, oppositely disposed elastic ring 101 is disposed between the other annular seat 96 and the metal ring 99. The elastic rings 180, T101 are press fitted in the respective annular seats 95, 96 and extend therefrom in opposite directions at an angle towards the opposite annular seats on the respective rings 98, 99. The angular disposition of the elastic rings 100, 101 is such as to press the metal rings 98, 99 towards each other to maintain the surfaces thereof in abutting contact. Also, the elastic ring maintains the metal ring 98 rotatively 7 fixed relatively to the hub 88, and the elastic ring 101 similarly maintains the metal ring 99 rotatively fixed relatively to the outer arm 78, whereby rotation of the mulling wheel 87 produces relative rotation of the metal rings 98, 99, while sealing engagement thereof is maintained by the elastic rings 100, 101. The elastic rings 100, 101 seal the area between the metal rings 98, 99 and the annular seats 95, 96, respectively.

The mulling wheel 87 fhas a tire 102 formed of rubber, or like yieldable material. The tire 102 is bonded to a metal band 103, and the tire 102 is secured to the hub 88 by press fitting the metal band 103 on the hub `88. Thus, the mulling wheel 87 is freely rotatable on the axle 80 by the bearings 81, 83, which are interposed Ibetween the hub 88 and `the axle 80. The bore 89 of the hub 88 is sealed at its outer end by the cover 92, and at its inner end by the rotating seal 97, the latter effecting a seal between the inner end of the bore 89 and the outer arm 78. Thus, the bearings 81, 83 are protected from the material that is dispersed in the receptacle 11. Were such materials to reach the bearings 81, 83, the latter could be damaged tand rendered ineffective in short order. The seals also serve to retain the lubricant for the bearings 81, 83 within the bore 89.

The inner arm 79 extends from the `boss 74 to a position adjacent the shaft 36. At the end of the inner arm 79 there is secured an eccentric disc 104 which abuts the shaft 36. A bolt 105 releasably secures the eccentric disc 104 to the inner arm 79, whereby the position of the eccentric disc 104 may be adjusted, thereby varying the spacing between the end of the inner arm 79 and the shaft 36 when the eccentric disc 104 is in contact with the shaft 36. The disposition of the outer arm 78 is adjusted accordingly, with the ultimate effect of adjusting the outermost position of the mulling wheel 87 relatively to the wall of the cylindrical receptable 11.

The second mounting arm 65 of the mulling assembly frame 60 has three pairs of apertures 106, 107, 108 which are spaced from each other and are disposed in two circular arcs that are concentric. A plow 109 is mounted on the second mounting arm 65. The plow 109 has an arm 110 with a bifurcated end 111 that has a pair of apertures which are spaced apart the same distance as the individual apertures of each pair of apertures 106, 107, 108. The second mounting arm 65 is received within the bifurcated end 111 of the plow arm 110 and is releasably secured thereto by a pair of bolts 112 extending through the apertures in the bifurcated end 111 of the plow arm 110 and one pair of the apertures 106, 107, 108, which is aligned therewith. The plow arm 110 extends towards the cylindrical shell of the receptacle 11 and terminates in an integral foot 113 that extends laterally to opposite sides of the arm 110. The foot 113 has a at surface facing inwardly of the receptacle shell 15, and this at surface is inclined with respect to a tangent to the receptacle shell 15, and is also inclined with respect to the axis of the shaft 36, the latter inclination being towards the upstream or feed end of the receptacle 11. A plow blade 114 is releasably secured to the foot 113. The plow blade 114 includes a pair of bolts 115 disposed one at each side of the arm 110 and extending through aligned apertures in the foot 113 to receive nuts that are turned on the bolts 115 to firmly secure the plow blade 114 to the foot 113. The leading edge of the plow blade 114 is disposed closely adjacent to the inner surface of the receptacle shell 15 and extends therefrom at the same angle of inclination as the foot 113.

The inclination of the plow blade 114 with respect to a tangent to the cylindrical shell 15 may be adjusted by selection of the pair of apertures 106, 107, 108 to which the plow 109 is secured by means of the bolts 112. The pairs of apertures 106, 107, 108 are disposed in concentric circular arcs having a center approximately on the leading edge of the plow blade 114, whereby in any position of adjustment of inclination of the plow blade 114, the spac- 8 ing between the leading edge of the plow blade 114 and the inner surface of the receptacle shell 15 remains substantially the same.

The inner cylindrical surface of the receptacle 11 provides the mulling surface on which the sand is mulled as it flows through the receptacle 11 in a longitudinal direction. In order to form a suitable surface on the receptacle shell 15, there is provided a liner 116 formed of rubber, or like yieldable material. The liner 116 is formed in three sections, of which two liner sections 117, 118 are of equal arcuate length and are secured to the receptacle shell 15, and the third liner section 119 is of shorter arcuate length and is secured to the cover 20. Except for the arcuate -length of the several sections 117, 118, 119 of the liner 116, the construction of these is the same, and accordingly, only one liner section need be described in detail.

The liner section 117 comprises a metal backing plate 120 which extends the length of the receptacle 11 from one end wall 16 to the other end wall 17. Bonded to the metal plate 120 is a sheet of rubber, or like yieldable material, which is the element of the liner 116 that actually forms the mulling surface inside the receptacle 11. The metal backing plate 120 of the liner section 118 is the element by which the liner section 118 is secured to the receptacle shell 15. For this purpose, the rubber sheet 121 is set back from each end of the metal backing plate 120 to expose the latter along a narrow strip. Curved metal lbars 122, 123 are placed against the metal backing plate 120 at the end walls 16, 17, respectively, for the purpose of securing the liner 116 to the receptacle shell 15. Each of the curved Ibars 122, 123 is of the same arcuate length and the same thickness as the rubber sheet 121, so that the curved bars 122, 123 are coextensive and flush therewith. Each curved bar 122, 123 has several tlush bolts 124 which extend through the curved bars 122, 123, the metal backing plate 120 and the receptacle shell 15 and project beyond the latter for the reception of suitable nuts by which the curved bars 122, 123 are firmly secured to the receptacle shell 15 and thereby secure the liner section 118 in place, as described.

As best seen in FIG. 2, each of the liner sections 117, 118 extends through one-half of the arcuate length of the receptacle shell 15, not including the arcuate length of the cover 20. The liner sections 117, 118 abut each other t-o form the liner 116 extending continuously around the fixed portion of the receptacle shell 15. The liner section 119 is coextensive with the arcuate extent of the cover 20, and when the latter is in closed position, the ends of the liner section 119 abut the exposed ends of the liner sections 117, 118, whereby the liner 116 extends through the full inner circumference of the receptacle shell 15, and the rubber sheet 121 thereof provides an endless mulling surface that faces inwardly of the receptacle shell 15 and is disposed around the axis of the shaft 36. As seen in FIG. 1, the liner section 117 is cut away at the discharge section 55 to provide an opening connecting to the discharge chute 56.

Each mulling assembly 57a-h is operative to mull the sand in the receptacle 11. The mulling, as such, is accomplished by the several mulling wheels 87 of the mulling assemblies 57a-h and the liner 116. The mulling action, comprising the pressing, kneading and mixing of the sand, takes place between the mulling wheels 87 and the liner 116. The sand is dispersed on the liner 116 about the axis of the shaft 36, and the mulling wheels 87 engage the sand that is so dispersed on the liner 116, and there is a pressing, kneading and mixing action of the mulling wheels 87 on the sand to accomplish the mulling of the sand. The sand as it flows longitudinally through the receptacle 15, and is dispersed therein, is highly labrasive in its action, on the elements of the apparatus, and particularly so with respect to the elements which are operative to work the sand. Thus, each mulling wheel 87 is provided with the tire 102 made of yieldable material, and likewise, the liner 116 includes the sheet 121 of yieldable material to form the mulling surface, which are more resistant to the wearing, abrasive action of the sand than would be the case with non-yieldable materials, for example, metal. The operation of the continuous muller will be described in greater detail hereinafter.

The construction of the mulling assembly 57a is typical of each of the mulling assemblies 57bh, each of which includes all the elements thereof which have been described heretofore; however, the mulling assembly 57a includes an additional element which is the intake accelerating plow 125, as best seen in FIGS. 1 and 2. A bar 126 is secured to the first mounting arm 64 of the frame 60 in a suitable manner, as by welding. The plow 125 has an arm 127 extending upwardly to meet the lower end of the bar 126 and is releasably secured to the latter by a pair of bolts 128. The bolts 128 may be released for the purpose of replacing the intake accelerating plow 125 if it should experience excessive wear. The plow 125 has a plow blade 129 which is disposed substantially parallel to the axis of the shaft 36, and is in front of the mulling wheel 37 to lead the latter in the direction ot movement thereof around the axis of the shaft 36, this being in a clockwise direction, as viewed in FIG. 2. The intake accelerating plow 125 meets the sand as it initially fiows into the receptacle 11, and gives such sand an initial acceleration or movement, and in effect disperses the sand to prevent it from piling up excessively in front of the mulling wheel S7 of the rst mulling assembly 57a. By reason of the gap between the plow blade 129 and the liner 116, a substantial amount of sand remains ahead of the mulling wheel 87 to be acted upon thereby. Other than as stated with respect to the mulling assembly 57a, the several mulling assemblies 57a-h are alike in construction.

At the discharge section 55 of the receptacle 11 there is provided a radially extending sweeper blade 130, as best seen in FIGS. 1 and 5. Near the end wall 17, a partial hub 131 is secured to the shaft 36, as by welding. The partial hub 131 has the same configuration as the several partial hubs 58, for the mulling assemblies 57a-h. The sweeper blade 130 has a hub portion 132 that is placed on the shaft 36 adjacent the partial hub 131, and the sweeper blade 130 is secured to the partial hub 131 by a plurality of bolts 133, which may be three in number. The sweeper blade 130 is formed as a planar element disposed in a plane that is placed laterally with respect to the shaft 36. The sweeper blade 130 rotates with the shaft 36 in front of the end wall 17. As the Sand flows downstream and reaches the discharge section 55 it would normally have a tendency to adhere to the end wall 17 and to accumulate on the same. However, the rotating sweeper blade 130 prevents such accumulation of the sand, and accordingly, the sand continuously discharge through the discharge chute S6 at the same rate as the rate of movement of the sand into and through the receptacle 11.

The operation of the mulling apparatus 10 will now be described. The sand flows into the receptacle 11 from the feed chute 53 and through the feed opening 51 at the feed or upstream end thereof. As the sand enters the receptacle 11, it is met by the intake accelerating plow 125 which starts the sand in movement around the axis of the shaft 36 and prevents an excessive accumulation of sand in front of the mulling wheel 87 of the mulling assembly 57a. The intake accelerating plow 125 impels the sand in a lateral direction with respect to the axis of the shaft 36. However, the sand also has a tendency to fan out upstream and downstream from the opposite side edges of the plow 125. On the upstream side the sand is blocked by the end wall 16. Accordingly, the movement of the sand impelled by the accelerating plow 125 is in a lateral direction and in a downstream direction. The mulling wheel 87 of the mulling assembly 57a follows closely be- 10 hind the intake accelerating plow 125, the mulling assembly 57a being moved in a clockwise direction by the shaft 36 about the axis of the latter, as viewed in FIG. 2.

The shaft 36 is rotated at a relatively high rate of speed, suiicient to cause the mulling wheel 87 to be moved outwardly towards the mulling surface of the liner 116 by centrifugal force. The limit of the outward movement of the mulling wheel 87 in response to the action of centrifugal force is determined by the upper arm 79 and the setting of the eccentric disc 104. The mulling action is found to be most effective when there is provided a gap between the periphery of the mulling wheel 87 and the mulling surface of the liner 116, for example as seen in FIG. 2. The maintenance of such a gap prevents the grains of sand from being crushed, which would otherwise occur, and the action of the mulling wheel 87 on the sand is then, in true effect, only a pressing, kneading and mixing action, which is the requisite action for properly combining the sand with the bonding ingredients. The optimum gap between the periphery of the wheel 87 and the mulling surface of the liner 116 may be different for different sands, different combinations of sand and bonding ingredients, and different operating conditions. Accordingly, the eccentric disc 104 may be set to provide the appropriate gap between the mulling wheel 87 and the mulling surface of the liner 116. The eccentric disc 104 also provides an adjustment for wear of the mulling wheel tire 102. As such tire 102 wears down, the gap increases and by resetting the eccentric disc 104 the gap may be closed and restored to its proper dimension.

As the mulling wheel S7 moves around the axis of the shaft 36 and over the mulling surface of the liner 116 to press, knead and mix the sand, it also packs the sand against the mulling surface. Such packed sand is removed from the mulling surface of the liner 116 by the plow 109 that follows behind the mulling wheel 87 in the direction of movement of the mulling assembly 57a around the axis of the shaft 36. The plow blade 114 has its leading edge disposed closely adjacent to the mulling surface of the liner 116, with sucient clearance being provided to prevent the plow blade 114 from damaging the liner 116. The plow blade 114 engages the sand that is packed on the mulling surface, to remove such sand therefrom by a scraping action. By reason of the speed of the plow 109 over the mulling surface of the liner 116, and the selected angle of the plow blade 114 with a tangent to the mulling surface, the engagement of the plow blade 114 with the sand causes the latter to be impelled in a lateral direction with respect to the axis of the shaft 36, and about the axis of the shaft 36 over the mulling surface, whereby such sand is broken up and dispersed in the receptacle 11. The sand fans out in an upstream and downstream direction from the plow blade 114, as an incident to being impelled in a lateral direction. In order not to impede or interfere with the impulsion and dispersion of the sand by the plow blade 114, the plow 109 is spaced a sufficient distance behind the mulling wheel S7 such that the sand effectively clears the mulling wheel 87 as it is impelled and dispersed by the plow 109.

It is a concomitant of the impelling action of the plow 109 on the sand that the sand is distributed around the circumference of the receptacle 11 and is substantially uniformly distributed over the mulling surface of the liner 116 throughout the circumference of the latter. Thus, the sand is mulled on the mulling surface of the liner 116 between it and the mulling wheels 87 throughout the circumference of the cylindrical mulling surface.

, As the sand is impelled laterally, it fans out from the plow blade 114 in upstream and downstream directions. However, the sand which fans out from the plow blade 114 in an upstream direction meets greater resistance to such movement than does the sand which fans out in a downstream direction, by reason of the fact that additional sand is continuously being delivered at the upstream end of the receptacle 11, while sand is continuously discharging from the discharge section 55 at the downstream end of the Areceptacle 11. Thus, there is a pressure head condition in the receptacle 11, whereby the sand flows in a stream through the receptacle 11 in a longitudinal direction from the feed or upstream end to the discharge or downstream end thereof, rather than being positively fed through the receptacle 11. Tn this manner, a given portion of sand flows longitudinally to the successive mulling positions a-lz along the length of the muller receptacle 11, to be successively mulled by the respective mulling assemblies 57a-h. The plows 109 do not act in any manner to positively feed the sand in a longitudinal direction downstream as do plows that are sharply angled or inclined with respect to the longitudinal axis. The plows 109 are operative to put the sand in motion and to create a dynamic condition of the sand, whereby the pressure head as above described is effective to produce a true downstream ow of the sand in a longitudinal direction through the receptacle 11.

Each of the plow blades 114 is inclined with respect to the axis of the shaft 36, the inclination being such as to form. a small angle between a plow blade 114 and the axis of the shaft 36, which diverges towards the upstream end of the receptacle 11. It appears that a relatively small inclination of the plow blade 114 relatively to the axis of the shaft 36, in either an upstream or a downstream direction, has a substantial effect on the rate of flow of sand longitudinally through the muller receptacle 11. The effectiveness with which the sand is mulled in the receptacle 11 is related to the amount of time during which the sand is retained in the receptacle 11, this being the time during which the mulling wheels 87 act on the sand to mull the same. This is generally termed the retention time of the sand in the muller apparatus 10.

The plow blades 114 would be disposed parallel to the axis of the shaft 36 for maximum effectiveness in dispersing the sand laterally with respect to the axis of the shaft 36 and throughout the circumference of the cylindrical shell 15, in order that the mulling action may take place over the full mulling surface of the liner 116. However, when the plow blades 114 are disposed parallel to the axis of shaft 36 it has been found that the sand will ow or feed through the muller receptacle 11 so quickly that the retention time of the sand in the receptacle 11 is insufficient to realize the maximum mulling effectiveness of the mulling assemblies 57a-h. Therefore, each of the plow blades 114 is disposed at a small angle of inclination in an upstream direction and with respect to the axis of the shaft 36, as has been described hereinabove. Such angle is of the order of approximately five to ten degrees. By reason of the relatively small inclination of the plow blades 114, there is no material effect on the action of the plow blades 114 to disperse the sand in the receptacle 11 about the axis of the shaft 36 and over the mulling surface of the liner 116. However, the plow blades have an additional effectiveness by reason of the inclination thereof in the upstream direction, which is to feed the sand in an upstream direction which, of course, is countercurrent to the downstream ow of the sand. Even though the plow blades 114 are inclined at a relatively small angle upstream, the feeding effect of such inclination is substantial; however, this feeding effect does not negative the downstream flow of the sand since the downstream feeding action, due to the dynamic condition of the sand and the pressure head thereof, is considerably greater than the upstream feeding action, due to the inclined plows. The total effect is that the sand continuously flows downstream, but by reason of the plow blades 114 being inclined in an upstream direction, the resultant rate of feed of the sand through the receptacle 11 is decreased; stated another way, the retention time of the sand in the receptacle is maintained at such level that the mulling effectiveness is not diminished by reason of the sand flowing through the receptacle 11 at too great a speed.

As clearly seen in FIG. 1, the mulling assemblies 57a-h are disposed at the successive positions a-h along the shaft 36, which positions are equally spaced. Thus, a given mass of sand is successively mulled by the mulling assemblies 57a-h as it ows longitudinally through the muller receptacle 11. The successive mulling assemblies 57a-h have a particular angular disposition one relatively to the other, which is that each mulling assembly 57 trails, or is disposed behind the preceding mulling assembly in the direction of rotation thereof about the axis of the shaft 36. In the preferred embodiment of the invention disclosed herein, the angle between one mulling assembly 57 and the successive mulling assembly 57 is less than so that when viewed along the shaft 36 the successive mulling assemblies 57a-h have the appearance of being disposed along a helix. The relative angular disposition of one mulling assembly 57 with respect to a preceding mulling assembly 57 is best illustrated in FIG. 2, wherein the mulling assembly 57a is illustrated in solid lines, and certain elements of mulling assembly 5717 are illustrated in phantom lines; the latter are identified as the mulling Wheel 87b and the plow 109b.

As the mulling wheel 87 moves around the axis of the shaft 36, each mulling wheel 87 also rotates about its own axis. The mulling wheels 87 do not rotate on the mulling surface of the receptacle liner 116. Rather, the mulling wheels 87 engage the sand on the mulling surface of the liner 116 and rotate relatively to the mulling surface. At all times, the mulling wheels 87 are thrust outwardly by the centrifugal force acting on the same, so that the mulling wheels 87 effectively press the sand between the peripheries of the mulling wheels 87 and the mulling surface of the receptacle liner 116. As the mulling wheels 87 thus work their way through the sand that is dispersed on the mulling surface, all the while rotating about their own axes, the mulling wheels 87 are effectively pressing, kneading and mixing the particles of the sand, whereby there is produced a complete homogeneous combination of the sand with the bonding ingredients, in which the individual grains of the sand are coated with the bonding ingredients.

The plow 109b follows behind the mulling wheel 87b and it scrapes the mulled sand from the mulling surface and disperses the sand over the mulling surface and about the axis of the shaft 36, as has been described. The 0peration, as described with respect to the mulling assemblies 57a, 57 b, repeats itself downstream as to the successive mulling assemblies 57a-h. The total effect of the operation is that the sand continuously ows through the muller receptacle 11 towards the discharge section 55; however, there is a retarding effect on the downstream flow of the sand by reason of the plow blades 114 being inclined in an upstream direction. Such retarding effect merely decreases the speed of flow of the sand through the receptacle 11 so that the retention time of the sand in the receptacle 11 is sufficient for effective mulling of the sand.

It believed that during the operation of the mulling apparatus 10 the sand is distributed on the mulling surface of the liner 116 is in cylinder from the upstream end to the discharge section 55 at the downstream end of the receptacle 11. It appears that such cylinder diverges internally towards the discharge section 102, so that, in effect, there is a downhill condition in the receptacle 11. Since the sand is always maintained in a dynamic condition of movement in the receptacle 11 by the action of the plows 109 dispersing the sand over the mulling surface, the sand readily flows downstream under the force of the pressure head that exists by reason of the sand being continuously fed in at the upstream end of the receptacle 11 and discharged at the discharge section 55.

The torsion bushings 67 provide a flexible or yieldable connection between the shaft 71 and the sleeve 66. The rubber cylinders 69 of the torsion bushings 67 have a neutral position and any distortion thereof from the neutral position gives rise to a force which opposes such distortion. This force may be characterized as the spring rate of the yieldable cylinders 69. The interposition of the torsion bushings 67 between the sleeve 66 and the shaft 71 produces a smoother operation of the mulling wheels 87 under the action of centrifugal force, in that the wheels 87 are not subjected to sudden and erratic thrusting thereof in response to the action of centrifugal force, or upon encountering uneven accumulations of sand on the mulling surface.

It has been found desirable to place the torsion bushings with the neutral position of the yieldable cylinders 69 located in such position, that the mulling wheels 87 in the idle position of the apparatus are placed at a position intermediate the periphery of the shaft 36 and the mulling surface of the liner 116. When the apparatus is in operation, the relatively high speed of rotation of the shaft 36 gives rise to a centrifugal force that thrusts the mulling wheels 87 to their maximum outer position, as determined by the selected position of the eccentric disc 104. In moving to such position, the yieldable cylinders 69 of the torsion bushings 67 are distorted by reason of the metal sleeves 68 turning relatively to the fixed sleeves 66 on the first mounting arms 64. The distortion of the torsion bushings 67 is greatest at the maximum outer position of the mulling wheels 87, and accordingly, the resisting force of the torsion bushings 67 is greatest at this position of the mulling wheels 87. The resisting force of the torsion bushings 67 acts in the opposite direction from the centrifugal force on the mulling wheels 87, and the effect is to reduce the centrifugal force. However, if for any reason the mulling wheels 87 move inwardly, then the resisting force of the torsion bushings 67 is reduced, andthe negative effect thereof on the centrifugal force is likewise reduced. The overall effect is a degree of compensation by the torsion bushings 67 for the loss of centrifugal force that occurs by reason of the mulling wheels 87 moving inwardly from their outermost positions. The torsion bushings 67 may be selected to provide such magnitude of resisting force and cushioning effect as may be desired for a given construction of the continuous muller 10.

The mulling apparatus which is described herein provides a means for practicing a novel method of mulling material, such .as sand. In such method, the sand is continuously delivered to and discharged from the receptacle within which the mulling is performed. The sand is dispersed in the receptacle and is distributed on a cylindrical mulling surface, whereby the sand continuously flows in a stream through the receptacle. The sand that is distributed on the mulling surface is mulled on such mulling surface. The mulling takes place concurrently with the fiow of the stream of sand through the receptacle. The total effect of the several steps is a process for continuously mulling sand such that the sand may be continuously delivered and fed into the receptacle to be mulled, and likewise, the sand is continuously discharged from the recept-acle after such mulling operation.

The improved continuous mulling apparatus described herein provides a means whereby the material ows continuously in a stream through the apparatus. Such flow is retarded for the purpose of maintaining the retention time of the sand in the receptacle at a sufficiently high leveT to effectively mull the material, since the mulling effectiveness is a function of the retention time of the sand. However, there is no disturbance of the overall continuous flowing condition of the material from the upstream end of the apparatus to the downstream end of the apparatus. In accordance with the invention the material is dispersed about the axis of the mulling apparatus in a lateral direction to distribute the material on the mulling surface, and is maintained in a dynamic condition for the downstream ow of the material through the apparatus, which is required for continuous operation. It is an inherent feature of the mulling operation disclosed herein that the material is very effectively aerated by reason of its dispersion in the apparatus, which causes the material to be broken up so that when ultimately discharged it is in a true granular form.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and applicant therefore wishes not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of the invention, what it is desired to secure by Letters Patent of the United States is:

1. Apparatus for continuously mulling material comprising, a receptacle disposed on a laterally extending axis, said receptacle extending along said axis to define a path of owfor material through the receptacle in a longitudinal direction from one end of the receptacle to the other end of the receptacle, said receptacle comprising a wall having an inwardly facing mulling surface on which the material is to be mulled, said mulling surface being disposed about said axis, mulling means in said receptacle to mull the material between the mulling means and said mulling surface as the material fiows through the receptacle, and longitudinally extending plow means inclined towards said one end of the receptacle and movable about said axis to engage the material as it flows through the receptacle and to disperse the material about the axis on the mulling surface and to retard the ow of the material from said one end of the receptacle to said other end of the receptacle for retention of the material in the receptacle during a sufficient time interval to effectively mull the same.

2. Apparatus for continuously mulling material as recited in claim 1, in which said plow means comprises a planar plow element.

3. Apparatus for continuously mulling material as recited in claim 1, in which said inclined plow means is disposed at a small angle with respect to said laterally extending axis.

4. Apparatus for continuously mulling material as recited in claim 1, in which said inclined plow means is disposed at an angle of the order of five to ten degrees with respect to said laterally extending axis.

5. Apparatus for continuously mulling material as recited in claim 1, in which said plow means comprises a planar plow element which is disposed at an angle relative to said mulling surface.

6. Apparatus for continuously mulling material comprising, a receptacle disposed on a laterally extending axis, said receptacle extending along said axis to define a path of ow for material through the receptacle in a longitudinal direction from one end of the receptacle to the other end of the receptacle, said receptacle comprising a wall having an inwardly facing mulling surface on which the material is to be mulled, said mulling surface being disposed about said axis, mulling means in said receptacle disposed at successive positions along said axis to successively mull the material as it flows through the receptacle, said mulling means being movable about said axis to mull the material between the mulling means and the mulling surface, and plow means disposed at a small angle of inclination in the direction of said one end of the receptacle and movable about said axis to engage the material as it flows through the receptacle and to disperse the material about the axis on the mulling surface and -to retard the ow of the material from said one end of the receptacle to said other end of the receptacle for retention of the material in the receptacle during a sufficient time interval to effectively mull the same.

7. Apparatus for continuously mulling material cornprising, a receptacle -disposed on a laterally extending axis, said receptacle extending along said axis to define a path of ow for material through the receptacle in a longitudinal direction from one end of the receptacle to the other end of the receptacle, said receptacle comprising a wall having an inwardly facing mulling surface on which the material is to be mulled, said mulling surface being disposed about said axis, mulling means in said receptacle disposed at successive positions along said axis to successively mull the 'material as it llows through the receptacle, said ymulling means being movable about said axis to mull the material between the mulling means and the mulling surface, and plows each movable about the axis, each plow including a planar blade disposed at a small angle of inclination in the direction of said one end of the receptacle with an edge thereof disposed adjacent the mulling surface and extending from the mulling surface at an angle to engage the material as it flows through the receptacle and to disperse the material about the axis on the mulling surface and to retard the flow of the material from said one end of the receptacle to said other end of the receptacle for retention of the material in the receptacle during a sufficient time interval to effectively mull the same.

8. Apparatus for continuously mulling material as recited in claim 7, in which said small angle of inclination of a plow blade is of the order of five to ten degrees with respect t-o said laterally extending axis.

9. Apparatus for continuously 'mulling material comprising, a receptacle disposed on a laterally extending axis, said receptacle extending along said axis to dene a path of flow for material through the receptacle in a longitudinal direction from one end of the receptacle to the other end f the receptacle, said receptacle comprising a Wall having an inwardly facing mulling surface on which the material is to be mulled, said mulling surface being disposed about said axis, mulling wheels in said receptacle disposed at successive positions along said axis to succesively mull the material a it flows through the receptacle, and a plow following behind each mulling wheel and movable about the axis, each plow including a planar blade disposed at a small angle of inclination in the direction of said one end of the receptacle with an edge thereof -disposed adjacent the mulling surface to scrape material from the mulling surface and extending from the mulling surface at an angle to engage the material as it flows through the receptacle and to disperse the material about the axis on the mulling surface and to retard the flow of material from said one end of the receptacle to said other end of the receptacle for retention of the material in the receptacle during a sufcient time interval to effectively mull the same.

10. Apparatus for continuously mulling material as recited in claim 9, in which said small angle of inclination of a plow is of the order of five to ten degrees with respect to said laterally extending axis.

References Cited by the Examiner UNITED STATES PATENTS 1,358,782 11/1920 Philippi 241-118 1,670,750 5/1928 Simpson 241-119 1,706,417 3/1929 Simpson 241-98 2,306,422 12/1942 Beardsley et al 241-156 2,750,163 6/1956 Loedige et al 259-109 WALTER A. SCHEEL, Primary Examiner.

R. JENKINS, Assistant Examiner. 

1. APPARATUS FOR CONTINUOUSLY MULLING MATERIAL COMPRISING A RECEPTACLE DISPOSED ON A LATERALLY EXTENDING AXIS, SAID RECEPTACLE EXTENDING ALONG SAID AXIS TO DEFINE A PATH OF FLOW FOR MATERIAL THROUGH THE RECEPTACLE IN A LONGITUDINAL DIRECTION FROM ONE END OF THE RECEPTACLE TO THE OTHER END OF THE RECEPTACLE, SAID RECEPTACLE COMPRISING A WALL HAVING AN INWARDLY FACING MULLING SURFACE ON WHICH THE MATERIAL IS TO BE MULLED , SAID MULLING SURFACE BEING DISPOSED ABOUT SAID AXIS, MULLING MEANS IN SAID RECEPTACLE TO MULL THE MATERIAL BETWEEN THE MULLING MEANS AND SAID MULLING SURFACE AS THE MATERIAL FLOWS THROUGH THE RECEPTACLE, AND LONGITUDINALLY EXTENDING PLOW MEANS INCLINED TOWARDS SAID ONE END OF THE RECEPTACLE AND MOVABLE ABOUT SAID AXIS TO ENGAGE TE MATERIAL AS IT FLOWS THROUGH THE RECEPTACLE AND TO DISPERSE THE MATERIAL ABOUT THE AXIS ON THE MULLING SURFACE AND TO RETARD THE 